Apparatus for making an endless filter string for cigarette filter plugs



1964 P. A. MULLER 3, 6 57 APPARATU; FOR MAKING AN ENDLESS FILTER STRING FOR CIGARETTE FILTER PLUGS Filed April 28, 1955 .7 Fig.8 Fig.9 FigJO i PAUL A. MULLER INVENTOR- ATTORNEYS desired shape and size.

United States Patent 3,161,557 APPARATUS FOR MAKING AN ENDLESS FEEL ER STRENGFQR (IKGARETTE FILTER PLUGS Paul A. Miiller, Rosenhngel, Herrliherg, Switzerland Filed Apr. 28, N55, Ser. No. 504,647 6 Qlairns. (til. 155 -462) The present invention relates to an automatically operating plant for producing an endless filter string suitable for immediate subsequent processing in filter plug and cigarette machines, and refers to further developments of the invention as setfonth in my co-pending U.S. Applica-v tion Serial No. 447,478, now US. Patent No. 2,847,086, dated August 12, 1958. This application is a continuationin-part of my copending application Serial No. 502,016, filed April 18, 1955, now Patent No. 2,995,481.

Filter strings of this type, which consist as a rule of crimped paper, are already used for the production of filter plugs. In this connection it is important for the filter plug and cigarette machine which processes the filter string that, as far as possible, an endless string of given shape and size be fed to the machine, as rapid working and smooth running condition of the latter depend on the uniform formation of said endless string. The starting material, however, from which such filter strings are usually made, is not yet available in endless Webs, but only in short or long strips. By Way of example, crimped paper, which is used for instance in 66 cm. wide webs with crimped grooves running transverse to the longitudinal direction of the web, is cut parallel to the crimped grooves into 4 cm. wide strips according to the lengths desired for the plugs to be produced; then several of these strips, four or five as a rule, are placed one on top of the other and fed in the longitudinal direction of the strips to a suitable deforming device which produces from this multi-layer web of strips a crimping paper string of the Each string is, of course, only 66 cm. wide, which leads to undesirable difiiculties in subsequent processing and always results in a certain number of defective filter plugs.

In order to produce an endless filter string from such has been made to stagger the superimposed individual strips in the longitudinal direction so that the points of junction of successive strips of the top layer are in different places from the points of the junction of the layer underneath. This does indeed result in an endless, layered strip web, but the latter has a plurality of junction points, which also leads to filter plugs of varying quality and to rejects.

The further suggestion, to paste the individual super- "imposed strips together at the jllllC'tlOIl points either by hand or mechanically, does not solve the present problem either. For substantially different properties of the material in respect to mechanical strength, porosity and ab-. sorptive capacity result at the pasted junction points so of the web of material. Further provided are folding and gathering members designed to reduce continuously the width of the web to an endless string of given shape and strips, which are for instance 66 cm. long, the suggestion set forth.

3,lfil,55? Patented Dec. 15, 1964 size, the material having a practically constant thickness and being virtually free from junction points.

The expression virtually free from junction points" refers to a filter string in which no junction points occur in-lengths of some 50 or 500 metres. Since, naturally, the virtually endless web of material unwinding from a delivery roll and fed to the arrangement does end once the magazine is empty and must be joined to the beginning of a full magazinefor which special means are provided-such junction points are to be regarded as a rare occurrence, at any rate in comparison with the methods usual hitherto which resulted in fifty to hundred junction points. A few typical embodiments of the invention will now be explained in detail in conjunction with FIGS. 1 to 13 of the attached drawing, in which:

FIGS. 1 and 2 are side elevation and top plan views, respectively-both partly in sectionof a typical embodiment according to the invention, shown in diagrammatic form;

FIGS. 3 and 4 are each folding means shown in perspective and cross-section, respectively;

FIGS. 5, 6 and 7 are each cross-sections through typical embodiments of a filterstring produced with the arrangement according to the invention, shown in diagrammatic form;

FIGS. 8, 9 and 10 are each verticalprojections and sectidns through various typical embodiments of deforming rollers used in connection with the invention;

7 FIGS. 11 and 12 areeach diagrammatic views of two overlapping webs of material.

' FIG. 13 is a modified schematic and fragmentary showing of two paper supply rolls for delivering two strip or web materials in overlapping relation, as depicted in,

FIG. 11 or FIG. 12, respectively.

The plant or arrangement illustrated in FIGS. 1 and 2 is, by way of example, designed for the production of an endless filter string consisting of a two-layer web of material. The one web material 1, which forms the carrier, unwinds from the delivery roll 2 and passes through moistening means 5a before it reaches deforming means hereinafter referred to, while the second web of material 3, which forms a covering of fibers, is not applied to the carrier web 1 by means of a laying roller 4 until the structure of 'the said carrier web 1 has already been subjected to pretreatment steps, as hereinafter grooves 6a, the initial web width, however, being at least approximately maintained. This, of course, can only berealized by a simultaneous stretching of the paper web it in a transverse direction, i.e., in the direction of the roller axes. Such a stretching of the material produces a desired structural alteration of the said ma- .terial, the paper fibres being pulled apart and, if the depth of the grooves issufiicient, disconnected longitudinal cracks appearing in the web; such a crimping of the paper web in the longitudinal direction substantially increases the absorptive capacity of the paper, which is advantageous for the present purpose. The axial distance and theradial dimensions. of the stamped grooves 6a, as well as their contours, can of course be selected 3 as desired so as to obtain a finer or coarser, or shallower or deeper longitudinal crimping of the paper web.

The rollers 6 and 7 are prefectly uniformly provided along their effective axial elongation with stamping grooves 61), 6c of the described type. It is of course also possible to provide only certain sections of the roller surfaces with such stamping grooves so that a paper web with longitudinally crimped and non-crimped strips lying next to one another will result.

The paper web 1 longitudinally crimped over its entire width in the typical embodiment according to FIGS. 1 and 2 then passes to a further pair of rollers 8 and 9, comprising a toothed roller 8 and a counter roller 9 provided with corresponding recesses, the said rollers serving to perforate the paper web 1. In the present case only a few annular zones of the surface of the roller 8 are provided with perforating teeth so that only four parallel longitudinal strips of the longitudinally crimped web of material 1 are perforated and a nonperforated longitudinal strip lies on either side of each perforated strip. If desired, the two rollers 8, 9 can also act as toothed roller and counter roller simultaneously, so that some of the perforation is effected from above and some from below. The perforating rollers 8 and 9 are preferably so designed that the edges of the individual perforation holes are frayed, which increases the filtering action of such a paper web. The toothed roller 8 and/or 9 while penetrating the previously corrugated and cracked web surface lends itself to the maintenance of the aforesaid initial web width.

The paper web 1, which is uniformly longitudinally crimped and perforated in strips is covered beneath the roller 4 with a fibre web 3, for instance a fleece con sisting of natural fibres such as cotton or cellulose, and the now two-layer web of material passes beneath the perforating pair of rollers 10, 11 which represent a further deforming means.

In this case the toothed roller 10 as well only has perforating teeth in separate annular zones of its surface and it is so designed that the paper covered with a web of fibres is perforated in those longitudinal strips which have not received any perforations by the agency of the pair of rollers 8, 9. The toothed roller 10 perforates both the web of fibres 3 and the web of paper 1, the perforating teeth being so designed that at least some fibres of the fibre web 3 are forced through the paper holes in the web of paper 1 underneath and project through such holes beyond the bottom of the paper web.

This causes the fibre web to be firmly anchored to the paper web on the one hand and on the other it also improves the adsorptive and absorptive action of the twolayer web of material. This organization of rollers 8, 9 and 10, 11 also aids in still maintaining the initial web width.

It is important that at least those longitudinal strips of the Web of material perforated by the pair of rollers 10, 11 should not undergo any further treatment that might influence their structure and surface before passing into the folding and gathering means, in order that the frayed edges defining each perforation and the fibre tufts are not pressed down against the surface of the web. If, therefore, as in the present case, further deformation and guiding of the material web through a pair of rollers 12, 13 is desired, before the said web passes into the inlet opening of the folding and gathering means 15, this deformation must concern the longitudinal strips" not treated by the last pair of perforating rollers 10, 11. Accordingly, knurling roller 12 has projecting irregularities only in those annular zones of its surface which effect a deformation of the longitudinal strips not perforated by the pair of rollers 10, 11. The irregularities of the knurling roller 12 and corresponding resilient collars on the counter roller 13 cause the structure of the material web to be compressed along the non-perforated strips, while the previously perforated longitudinal strips pass through the pair of rollers 12, 13 untouched. In this way the inlet opening 14 of the folding and gathering means 15 is supplied with a material web which consists of parallel longitudinal strips of varying structure, wherein a longitudinal strip of less mechanical strength but increased obsorptive capacity and filtering efficiency is always adjacent a longitudinal strip of greater mechanical strength and lower swelling capacity.

If desired, before the material web enters the folding and gathering members 15, it can be split up or cut into two or more parallel part webs, for which purpose suitably arranged knife rollers can be provided. By way of example, the knurling roller 12 in FIG. 2 is fitted in the centre with a knife-like cutting ring 12a, whereby the twolayer material web is cut in the middle into two part webs.

The material web entering the folding and gathering member 15 must be as invariable as possible in its structure. If, for instance, the paper web 1 has to be made flexible before passing through the longitudinal crimping and transverse stretching rollers 6, 7 so as to give it adequate deformability for the subsequent deformation, it should be stiffened at a suitable point of the arrangement by means of appropriate after-treatment means so as to ensure that the properties of the filter string leaving the folding and gathering member 15 will not alter even over a long period of time. By way of example, it has proved suitable with some harder kinds of paper to make the paper web flexible by moistening it with atomized water or other wet medium contained in tank 5a before it enters the rollers 6, 7. In this case the web of material, the structure of which has been altered, must then be subjected to an appropriate after-treatment after leaving the pair of rollers 8, 9. It is possible to use for this purpose a smooth, electrically heated plate 9a, for instance, over which the material web slides, is gently pressed by means of compressed air discharged from nozzles 9b and is freed from undesirable moisture. If desired, it is also possible to achieve a reduction in the web width by means of air streams acting on the sides of the still easily deformable paper web. Following this or another suitable after-treatment the material web must at any rate be in such a condition that no changes in its structure need be feared over a long period of time.

The folding and gathering member 15 consists of a flat funnel 16 which continuously decreases in width from the inlet opening 14 and opens out into a narrow nozzleshaped channel 17, the cross-section of which corresponds .to the desired shape and size of the endless filter string to be produced. The dimensions of the inlet opening are conformed to the width and thickness of the material web so as to ensure that the latter enters the funnel smoothly. The lateral gathering of the web material by means of the interior of the funnel which narrows at the sides and increases in height can be facilitated by the incorporation of folding means, two typical embodiments of which are illustrated in FIGS. 3 and 4.

FIG. 3 shows a part of the fiat funnel 16 immediately behind the inlet opening, the direction of arrow 18 indicating the direction of travel of the Web material in the funnel 16. The underside of the funnel 16 is provided in this case with a ribbed plate 19 which has a series of ribs 20 running parallel in the direction of arrow 18, the height of which ribs increases across the underside in the direction of arrow 18, the distance between the said ribs decreasing as the flat funnel 16 narrows. Between the ribs 20 guide grooves are thus produced, by means of which the web material passing over the ribbed plate 19 is regularly folded.

In the case of the folding means seen in FIG. 4 the top side 21 of the fiat funnel 16 is designed by way of example as a ribbed plate with longitudinal ribs 22 and the underside 23 is so shaped that a corrugated funnel channel 24 is produced. The amplitude of the corrugations of the channel 24 increases in the direction of transit,

i.'e., the height of the ribs 22 increases, while at the same time the distance between adjacent ribs 22 decreases, which results in a progressive corrugation and folding of the web material passing through.

To overcome the friction which the web material undergoes during folding and gathering in the funnel 16, a feed device for the material string is provided in the channel 17. This device consists, by way of example, of two endless conveyor belts 25 and 26 which are each driven by a driving wheel 27 and 28 respectively, pass over guide rollers 29, 30 and 31, 32 respectively and each form at opposite points a part of the wall of the outlet channel 17. The speed of the conveyor belts is adjusted to the speed of the web material entering the flat funnel, which latter speed is determined by the aforesaid deforming rollers.

On emerging from the nozzle-shaped channel 17 of the folding and gathering member 15 the endless filter string has the desired shape and size. The gathering process has compressed the material so that the filter string has the tendency to, expand in a radial direction. In order to prevent this, the filter string is passed, after emerging from the folding and gathering member 15, through an apparatus 33 in which the string is encased in known manner with a sheath or, envelope, thus ensuring that the desired shape and size of. the string will be maintained.

The resultant filter string a diagrammatically reproduced in cross-section in FIGS. 5, 6 and 7. In the sheath 34 there is, in FIG. 5, a crimped paper web 35 which has been folded several times, the gathering having been affected without folding means. FIG. 6 shows a web material similarly gathered without folding means and consisting of a carrier web 36 and a covering of fibres 3'7, i.e., a web material, such as is produced in the arrangement according to FIGS. 1 and 2. Finally, FIG. 7 indicates a filter string which is produced by regular folding of four part Webs 38, 39, 4t), 41, each of them being composed of two layers.

The roller deforming means indicated in the typical embodiment according to FIGS. 1 and 2 represent, of course, only some of the many possible kinds of such deforming means. By way of example, more than one pair of rollers with interlocking annular stamping edges can be arranged in series in order to achieve an intensive longitudinal crimping. If, in this case, the axial distance between adjacent stamping edges is made smaller in each successive pair of rollers, the progressive grooving of the web material will be accompanied at the same time by a reduction of the width of said web, which is desirable with some materials that tolerate only slight stretching in a transverse direction. At least one roller of the successive roller pairs of the various deforming means is always driven. If, although the rollers have the same diameter, the following rollers are driven at a higher speed than the preceding rollers, then the web material will be additionally stretched in the longitudinal direction. The same effect can be achieved in the case of roller pairs rotating at the same speed by making the diameter of following roller pairs larger.

Besides the toothed rollers and knurling rollers, which are indicated in FIGS. 1 and 2, deforming rollers according to FIG. 8 can also be used which consist of rollers 42 and 43 acting as a top and bottom stamping die respectively, it being possible to provide irregularities of any desired shape. In this case care should merely be taken to see that the distance in the longitudinal direction be tween successive irregularities on the rollers is small in relation to 10 mm. so as always to obtain an approximately equal number of such stampings per filter plug when the endless filter string is subdivided into individual filter plugs. Surface zones of such deforming rollers can also be provided with oblique toothing 44, as indicated in FIG. 9. In addition, various shapes of grooves 621, do can be selected from the longitudinal crimping rollers 6, 7, as indicated in FIG. 10. Finally, it is also possible to roughen the smooth surface zones of a web material on one or both sides by means of suitable brush-type rollers. As can be seen from the description of the arrangement according to FIGS. 1 and 2, as well as from the possible alternatives of the said arrangement, virtually endless filter strings can be successfully produced. Since the webs of material to be worked are as a rule fed from a delivery roll (2 in FIGS. 1 and 2), the arrangement must be stopped when the delivery roll is used up and a new roll inserted. Since, however, such an interruption is in most cases undesirable, means can be provided which facilitate a simple transition from the end of the one roll to the beginning of the next.

For this purpose the arrangement concerned is equipped with two delivery rolls for each of the various web materials, i.e., two delivery rolls 2a, 2111 (FIG. 1) for the paper web 1 in the typical embodiment according to FIGS. 1 and 2. Once the roll 2a with the paper web 111 has run out, the end of the paper web 1a is joined to the beginning of the paper web lib on roll 2b and this delivery roll is unwound, while the empty roll 2a is replaced by a full one and the process can be repeated inversely when the roll 2b has run out. It must. however, be ensured that the point of junction of the webs 1a/ 1b, after passing through the deforming means and the folding and gathering member 15, yields the same thickness of material as the pr ceding and following section of the filter string in order to avoid rejects. For this purpose the material webs la/ 1b are always joined in such a way that at each point of the overlap the total amount of material in the string is constant and equal to the amount of material in the sections of the material which do not overlap. Two typical embodiments are illustrated in FIGS. 11 and 12, in which the web ends are cut to a point and overlap only to such an extent that the pieces missing in the Web 1e are exactly equal in area to the additional pieces present in the web 1b at the relevant point. It is advantageous to secure to the arrangement suitable cutting tools arranged in mirror-picture fashion but similarly shaped, by means of which tools, first the beginning of the spare roll and than the end undwinding from the empty roll are cut to the correct size; whereupon the beginning and the end are placed on top of one another, as can be seen from FIGS. 11 and 12, and conveyed together to the first deforming means. It is not necessary in this case to fasten the two webs together as the joint deformation of the two webs, particularly the perforation, ensures ade quate adhesion.

Having now particularly ascertained and described the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. A plant for producing a filter member for processing the same in filter plug and cigarette machines, comprising: supply means for feeding an elongated paper web along a path; deforming and stretching means arranged along said path and including a plurality of pairs of rollers, one pair of said rollers being provided with annular stamping means for working upon the paper web to stretch the paper web in transverse direction of said path and form longitudinal corrugations therein, and another pair of said rollers including a roller provided with peripheral teeth for perforating the paper web thereacross at spaced locations thereof to provide holes having frayed edges in the paper web; and means for folding and gathering the paper web arranged along said path subsequent to said deforming and streching means and including means to progressively increase the amplitude of the corrugations in the paper web during passage thereof through said folding and gathering means.

2. A plant according to claim 1, including means for imparting flexibility to the paper web arranged along the path forwardly of the deforming and stretching means and including means for moistening the paper web.

3. Apparatus for treating paper strip material preparatory to laterally gathering and shaping the same into a 7 generally cylindrical string adapted to be cut into plugs for use as filters for cigarette smoke, comprising: means for feeding paper strip material along a predetermined path; means arranged along said path for moistening and softening the strip material; deforming and stretching means arranged along said path subsequent to said moistening means and including a plurality of pairs of roller means, one pair of said roller means being provided with peripheral stamping edges engageable with the softened strip material for stretching the same transversely and forming longitudinal corrugations therein, and another pair of said roller means being provided with peripheral teeth for perforating the strip material at a plurality of spaced locations to provide holes having frayed edges in the strip material; and drying means arranged along said path subsequent to said deforming and stretching means to dry the material while in strip form and set therein the corrugations formed by the deforming and stretching means without otherwise altering the shape of the material.

4. The structure defined in claim 3 including folding and gathering means arranged along the path subsequent to the drying means for laterally gathering and shaping the strip material into a generally cylindrical string.

5. Apparatus for treating paper strip material preparatory to laterally gathering and shaping the same into a generally cylindrical string adapted to be cut into plugs for use as filters for cigarette smoke, comprising: means for feeding paper strip material along a predetermined path; means arranged along said path for moistening and softening the strip material; deforming and stretching means arranged along said path subsequent to said moistening means and including at least two pairs of driven roller means, a first pair and a second pair arranged subsequently thereto, each of said roller means being 8 provided with peripheral stamping edges engageabie with the softened strip material for stretching the same transversely and'forming longitudinal corrugations therein, and said second pair being driven at a peripheral speed greater than that of said first pair to stretch the material longitudinally; and drying means arranged along said path subsequent to said deforming and stretching means to dry the material while in strip form and set therein the corrugations formed by the deforming and stretching means without otherwise altering the shape of the material.

6. The structure defined in claim 5 including folding and gathering means arranged along the path subsequent to the drying means for laterally gathering and shaping the strip material into a generally cylindrical string.

References Cited in the file of this patent UNITED STATES PATENTS 1,550,084 Lorenz Aug. 18, 1925 1,661,393 Stickney Mar. 6, 1928 1,680,203 Cannard Aug. 7, 1928 1,980,563 Walker Nov. 13, 1934 2,001,709 Davidson May 21, 1935 2,158,087 Rowe et al. May 16, 1939 2,164,702 Davidson July 4, 1939 2,245,014 Sherman June 10, 1941 2,320,092 Miller May 25, 1943 2,389,435 Karlstrom Nov. 20, 1945 2,423,294 Colesworthy July 1, 1947 2,475,789 Kunz July 12, 1949 2,628,656 Stevenson Feb. 17, 1953 FOREIGN PATENTS 420,464 Great Britain Dec. 3, 1934 

1. A PLANT FOR PRODUCING A FILTER MEMBER FOR PROCESSING THE SAME IN FILTER PLUG AND CIGARETTE MACHINES, COMPRISING; SUPPLY MEANS FOR FEEDING AN ELONGAGED PAPER WEB ALONG A PATH: DEFORMING AND STRETCHING MEANS ARRANGED ALONG SAID PATH AND INCLUDING A PLURALITY OF PAIRS OF ROLLERS, ONE PAIR OF SAID ROLLER BEING PROVIDED WIHT ANNULAR STAMPING MEANS FOR WORKING UPON THE PAPER WEB TO STRETCH THE PAPER WEB IN TRANSVERSE DIRECTION OF SAID PATH AND FORM LONGITUDINAL CORRUGATIONS THEREIN, AND ANOTHER PAIR OF SAID ROLLERS INCLUDING A ROLLER PROVIDED WITH PERIPHERAL TEETH FOR PERFORATING THE PAPER WEB THEREACROSS AT SPACED LOCATIONS THEREOF TO PROVIDE HOLES HAVING FRAYED EDGES IN THE PAPER WEB; AND MEANS FOR FOLDING AND GATHERING THE PAPER WEB ARRANGED ALONG SAID PATH SUBSEQUENT TO SAID DEFORMING AND STRECHING MEANS AND INCLUDING MEANS TO PROGRESSIVELY INCRESE THE AMPLITUDE OF THE CORRUGATION IN THE PAPER WEB DURING PASSAGE THEREOF THROUGH SAID FOLDING AND GATHERING MEANS. 